1. Field of the Invention
The present invention pertains to the field of Lighting Fixtures and more particularly to a fluorescent lighting fixture having an adjustable beam pattern.
2. Prior Art
Most current fluorescent lighting fixtures have a fixed lighting pattern. That is, the lamps and reflector direct and concentrate the light to focus on a fixed area, thereby limiting the installation flexibility. The lighting fixtures create a situation wherein, in many cases, the application area either is over or under illuminated. The present invention resolves this limitation through providing a means to smoothly transition between a very wide to very narrow illumination distribution pattern.
An additional issue is that existing lighting fixtures are frequently limited to static direct or indirect lighting, or a mixture of both. Direct lighting provides illumination below the plane of the lighting fixture whereas indirect lighting provides illumination above the plane of the lighting fixture. The present invention also provides a method to mix adjustable direct with adjustable indirect lighting as suitable with the particular installation to give the most pleasing lighting effect.
A further issue is that the addition of more lamps to the fixture, to increase lighting intensity while maintaining high efficiency, causes an increase in width of the lighting fixture, which may become large enough that fitting it into the available space may be problematical. The present invention resolves this issue by placing two lamps into each special optically designed cavity to provide a smooth lighting distribution while maintaining high efficiency unavailable with simple bend single cavity per lamp reflectors.
Most fluorescent lighting fixtures in the marketplace make installation difficult in that removal of the reflector may be required to access the lamp socket wiring. Additionally, the installer is required to work over his head through the bottom of the fixture to access the ballasts and wire the fixture to power or to another fixture. The present invention resolves these issues by making the socket tray accessible without removing the reflector and placing access to the ballasts and wiring from the top, which is safer and easier from a human factors standpoint.
Additionally, the prior art generally does not provide for a choice of mounting means within a singular design. The present invention provides for several common mounting methods as accessories to meet the needs of the specific application. Tandem mounting, classical chain hangers, and flush mounting methods are incorporated into the design.